example/fusexmp.c

   1 /*
   2     FUSE: Filesystem in Userspace
   3     Copyright (C) 2001-2007  Miklos Szeredi <miklos@szeredi.hu>
   4
   5     This program can be distributed under the terms of the GNU GPL.
   6     See the file COPYING.
   7
   8     gcc -Wall `pkg-config fuse --cflags --libs` fusexmp.c -o fusexmp
   9 */
  10
  11 #define FUSE_USE_VERSION 26
  12
  13 #ifdef HAVE_CONFIG_H
  14 #include <config.h>
  15 #endif
  16
  17 #ifdef linux
  18 /* For pread()/pwrite() */
  19 #define _XOPEN_SOURCE 500
  20 #endif
  21
  22 #include <fuse.h>
  23 #include <stdio.h>
  24 #include <string.h>
  25 #include <unistd.h>
  26 #include <fcntl.h>
  27 #include <dirent.h>
  28 #include <errno.h>
  29 #include <sys/time.h>
  30 #ifdef HAVE_SETXATTR
  31 #include <sys/xattr.h>
  32 #endif
  33
  34 static int xmp_getattr(const char *path, struct stat *stbuf)
  35 {
  36     int res;
  37
  38     res = lstat(path, stbuf);
  39     if (res == -1)
  40         return -errno;
  41
  42     return 0;
  43 }
  44
  45 static int xmp_access(const char *path, int mask)
  46 {
  47     int res;
  48
  49     res = access(path, mask);
  50     if (res == -1)
  51         return -errno;
  52
  53     return 0;
  54 }
  55
  56 static int xmp_readlink(const char *path, char *buf, size_t size)
  57 {
  58     int res;
  59
  60     res = readlink(path, buf, size - 1);
  61     if (res == -1)
  62         return -errno;
  63
  64     buf[res] = '\0';
  65     return 0;
  66 }
  67
  68
  69 static int xmp_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
  70                        off_t offset, struct fuse_file_info *fi)
  71 {
  72     DIR *dp;
  73     struct dirent *de;
  74
  75     (void) offset;
  76     (void) fi;
  77
  78     dp = opendir(path);
  79     if (dp == NULL)
  80         return -errno;
  81
  82     while ((de = readdir(dp)) != NULL) {
  83         struct stat st;
  84         memset(&st, 0, sizeof(st));
  85         st.st_ino = de->d_ino;
  86         st.st_mode = de->d_type << 12;
  87         if (filler(buf, de->d_name, &st, 0))
  88             break;
  89     }
  90
  91     closedir(dp);
  92     return 0;
  93 }
  94
  95 static int xmp_mknod(const char *path, mode_t mode, dev_t rdev)
  96 {
  97     int res;
  98
  99     /* On Linux this could just be 'mknod(path, mode, rdev)' but this
 100        is more portable */
 101     if (S_ISREG(mode)) {
 102         res = open(path, O_CREAT | O_EXCL | O_WRONLY, mode);
 103         if (res >= 0)
 104             res = close(res);
 105     } else if (S_ISFIFO(mode))
 106         res = mkfifo(path, mode);
 107     else
 108         res = mknod(path, mode, rdev);
 109     if (res == -1)
 110         return -errno;
 111
 112     return 0;
 113 }
 114
 115 static int xmp_mkdir(const char *path, mode_t mode)
 116 {
 117     int res;
 118
 119     res = mkdir(path, mode);
 120     if (res == -1)
 121         return -errno;
 122
 123     return 0;
 124 }
 125
 126 static int xmp_unlink(const char *path)
 127 {
 128     int res;
 129
 130     res = unlink(path);
 131     if (res == -1)
 132         return -errno;
 133
 134     return 0;
 135 }
 136
 137 static int xmp_rmdir(const char *path)
 138 {
 139     int res;
 140
 141     res = rmdir(path);
 142     if (res == -1)
 143         return -errno;
 144
 145     return 0;
 146 }
 147
 148 static int xmp_symlink(const char *from, const char *to)
 149 {
 150     int res;
 151
 152     res = symlink(from, to);
 153     if (res == -1)
 154         return -errno;
 155
 156     return 0;
 157 }
 158
 159 static int xmp_rename(const char *from, const char *to)
 160 {
 161     int res;
 162
 163     res = rename(from, to);
 164     if (res == -1)
 165         return -errno;
 166
 167     return 0;
 168 }
 169
 170 static int xmp_link(const char *from, const char *to)
 171 {
 172     int res;
 173
 174     res = link(from, to);
 175     if (res == -1)
 176         return -errno;
 177
 178     return 0;
 179 }
 180
 181 static int xmp_chmod(const char *path, mode_t mode)
 182 {
 183     int res;
 184
 185     res = chmod(path, mode);
 186     if (res == -1)
 187         return -errno;
 188
 189     return 0;
 190 }
 191
 192 static int xmp_chown(const char *path, uid_t uid, gid_t gid)
 193 {
 194     int res;
 195
 196     res = lchown(path, uid, gid);
 197     if (res == -1)
 198         return -errno;
 199
 200     return 0;
 201 }
 202
 203 static int xmp_truncate(const char *path, off_t size)
 204 {
 205     int res;
 206
 207     res = truncate(path, size);
 208     if (res == -1)
 209         return -errno;
 210
 211     return 0;
 212 }
 213
 214 static int xmp_utimens(const char *path, const struct timespec ts[2])
 215 {
 216     int res;
 217     struct timeval tv[2];
 218
 219     tv[0].tv_sec = ts[0].tv_sec;
 220     tv[0].tv_usec = ts[0].tv_nsec / 1000;
 221     tv[1].tv_sec = ts[1].tv_sec;
 222     tv[1].tv_usec = ts[1].tv_nsec / 1000;
 223
 224     res = utimes(path, tv);
 225     if (res == -1)
 226         return -errno;
 227
 228     return 0;
 229 }
 230
 231 static int xmp_open(const char *path, struct fuse_file_info *fi)
 232 {
 233     int res;
 234
 235     res = open(path, fi->flags);
 236     if (res == -1)
 237         return -errno;
 238
 239     close(res);
 240     return 0;
 241 }
 242
 243 static int xmp_read(const char *path, char *buf, size_t size, off_t offset,
 244                     struct fuse_file_info *fi)
 245 {
 246     int fd;
 247     int res;
 248
 249     (void) fi;
 250     fd = open(path, O_RDONLY);
 251     if (fd == -1)
 252         return -errno;
 253
 254     res = pread(fd, buf, size, offset);
 255     if (res == -1)
 256         res = -errno;
 257
 258     close(fd);
 259     return res;
 260 }
 261
 262 static int xmp_write(const char *path, const char *buf, size_t size,
 263                      off_t offset, struct fuse_file_info *fi)
 264 {
 265     int fd;
 266     int res;
 267
 268     (void) fi;
 269     fd = open(path, O_WRONLY);
 270     if (fd == -1)
 271         return -errno;
 272
 273     res = pwrite(fd, buf, size, offset);
 274     if (res == -1)
 275         res = -errno;
 276
 277     close(fd);
 278     return res;
 279 }
 280
 281 static int xmp_statfs(const char *path, struct statvfs *stbuf)
 282 {
 283     int res;
 284
 285     res = statvfs(path, stbuf);
 286     if (res == -1)
 287         return -errno;
 288
 289     return 0;
 290 }
 291
 292 static int xmp_release(const char *path, struct fuse_file_info *fi)
 293 {
 294     /* Just a stub.  This method is optional and can safely be left
 295        unimplemented */
 296
 297     (void) path;
 298     (void) fi;
 299     return 0;
 300 }
 301
 302 static int xmp_fsync(const char *path, int isdatasync,
 303                      struct fuse_file_info *fi)
 304 {
 305     /* Just a stub.  This method is optional and can safely be left
 306        unimplemented */
 307
 308     (void) path;
 309     (void) isdatasync;
 310     (void) fi;
 311     return 0;
 312 }
 313
 314 #ifdef HAVE_SETXATTR
 315 /* xattr operations are optional and can safely be left unimplemented */
 316 static int xmp_setxattr(const char *path, const char *name, const char *value,
 317                         size_t size, int flags)
 318 {
 319     int res = lsetxattr(path, name, value, size, flags);
 320     if (res == -1)
 321         return -errno;
 322     return 0;
 323 }
 324
 325 static int xmp_getxattr(const char *path, const char *name, char *value,
 326                     size_t size)
 327 {
 328     int res = lgetxattr(path, name, value, size);
 329     if (res == -1)
 330         return -errno;
 331     return res;
 332 }
 333
 334 static int xmp_listxattr(const char *path, char *list, size_t size)
 335 {
 336     int res = llistxattr(path, list, size);
 337     if (res == -1)
 338         return -errno;
 339     return res;
 340 }
 341
 342 static int xmp_removexattr(const char *path, const char *name)
 343 {
 344     int res = lremovexattr(path, name);
 345     if (res == -1)
 346         return -errno;
 347     return 0;
 348 }
 349 #endif /* HAVE_SETXATTR */
 350
 351 static struct fuse_operations xmp_oper = {
 352     .getattr    = xmp_getattr,
 353     .access     = xmp_access,
 354     .readlink   = xmp_readlink,
 355     .readdir    = xmp_readdir,
 356     .mknod      = xmp_mknod,
 357     .mkdir      = xmp_mkdir,
 358     .symlink    = xmp_symlink,
 359     .unlink     = xmp_unlink,
 360     .rmdir      = xmp_rmdir,
 361     .rename     = xmp_rename,
 362     .link       = xmp_link,
 363     .chmod      = xmp_chmod,
 364     .chown      = xmp_chown,
 365     .truncate   = xmp_truncate,
 366     .utimens    = xmp_utimens,
 367     .open       = xmp_open,
 368     .read       = xmp_read,
 369     .write      = xmp_write,
 370     .statfs     = xmp_statfs,
 371     .release    = xmp_release,
 372     .fsync      = xmp_fsync,
 373 #ifdef HAVE_SETXATTR
 374     .setxattr   = xmp_setxattr,
 375     .getxattr   = xmp_getxattr,
 376     .listxattr  = xmp_listxattr,
 377     .removexattr= xmp_removexattr,
 378 #endif
 379 };
 380
 381 int main(int argc, char *argv[])
 382 {
 383     umask(0);
 384     return fuse_main(argc, argv, &xmp_oper, NULL);
 385 }